Quick answer
Preliminary costs in construction are the indirect, time-related costs of running a job before and during production: site setup, supervision, temporary utilities, hoisting, security, cleaning and compliance. They are usually priced as a lump sum or a monthly rate and typically run 5–15% of direct construction cost, depending on project type, duration and site constraints.
- Preliminaries are time-based, so duration drives the number more than square footage does.
- They are not the same as general conditions, though many contractors use the terms interchangeably.
- Missing items are usually hoisting, temporary power, winter protection and final cleaning.
- Price preliminaries as a monthly rate times duration, then add one-time setup and removal costs.
What Are Preliminary Costs in Construction?
Preliminary costs in construction are the pre-construction and general-condition costs that are not part of the permanent installed work but are required to execute the project. They cover site mobilization, temporary utilities, temporary facilities, supervision, safety, quality control, permits, insurance, bonds, and closeout. If you are preparing a bid, these costs sit alongside your trade pricing and often decide whether you win or lose the job.
The term varies by contract format. Some documents call them preliminary and general costs, others use general conditions, and CSI-based specifications place many of them under Division 01 General Requirements. On a typical commercial project, preliminary costs in construction run about 5–15% of total construction cost, though that range shifts with project size, duration, and location. A short tenant fit-out may carry a lower percentage, while a long-duration heavy civil job can push it higher.
What are preliminary costs really doing? They keep the job running. Supervision, temporary power, and safety programs are not permanent work, but without them the permanent work does not happen. Because they are time-based, they are also a major driver of bid competitiveness and cash flow. Underestimating them can wipe out your margin before the first invoice.
If you need help building a defensible preliminary number, preliminary estimating services can give you a line-item breakdown you can carry into the bid. For a broader view of how these costs fit into a full estimate, see construction cost estimating.
Preliminary costs are time-based, so schedule duration affects them as much as scope. A two-month delay can add more to your general conditions than a small trade package.
Preliminary Costs vs General Conditions
General conditions are the direct project overhead costs required to manage and support the work on site. Preliminary costs is a broader term that can include general conditions plus pre-construction costs, permits, and fees. In some markets, the phrase preliminary and general costs (P&G) is used interchangeably with general conditions, so always read the contract definition before you price the package.
The closest standard classification for many of these items is CSI MasterFormat Division 01 General Requirements, which covers general conditions, temporary facilities, submittals, quality control, and closeout. UniFormat takes an element-based view and may group some preliminary costs under project overhead or common requirements. Neither system is a perfect match, so estimators often map preliminary items to Division 01 for bid forms and to UniFormat for conceptual budgets.
The table below shows how typical items usually fall.
| Item | General Conditions | Broader Preliminary Costs |
|---|---|---|
| Site supervision and project management | Yes | Yes |
| Temporary facilities and utilities | Yes | Yes |
| Safety and quality control programs | Yes | Yes |
| Building permits and impact fees | Usually no | Yes |
| Design and professional fees | Usually no | Yes |
| Insurance and bonds | Sometimes | Yes |
| Closeout and as-built documents | Yes | Yes |
Use the contract as your guide. If the owner carries permits or design fees separately, do not double-count them in your general conditions. For help sorting this on a commercial bid, commercial estimating services can align your Division 01 pricing with the bid form. General contractors who self-perform management should also review general contractor estimating to keep overhead and field supervision separated correctly.
Never assume the owner pays for permits. Read the supplementary conditions and the permit matrix before you carry a dollar in your general conditions.
Preliminary Cost Items List
Use this preliminary cost items list as a starting checklist, then tailor it to your project delivery method and contract. Not every item applies to every job, and some may be carried by the owner or construction manager rather than the general contractor. Walk the list against the specifications before you finalize your construction preliminary cost breakdown.
- Site mobilization: Move-in, staging, temporary roads, and demobilization at the end of the job.
- Temporary facilities: Site office, storage trailers, temporary toilets, first aid, and cleaning.
- Temporary utilities: Temporary power, temporary water, temporary lighting, and temporary heating or cooling.
- Site protection: Temporary fencing, barricades, dust control, and security.
- Project management and supervision: Project manager, superintendent, project engineer, and clerical support.
- Safety program: PPE, fall protection, signage, training, and safety officer time.
- Quality control: QC manager, mockups, testing coordination, and rework tracking.
- Permits and fees: Building permit fees, impact fees, utility connection fees, and inspection fees.
- Professional services: Design fees, engineering, surveying, and specialty consultants.
- Testing and inspection: Concrete testing, compaction testing, special inspections, and third-party review.
- Insurance and bonds: Construction insurance, performance bond, payment bond, and builder's risk.
- Schedule and submittals: Schedule development, updates, submittal log, and shop drawing review.
- Closeout: As-built drawings, O&M manuals, closeout documents, training, and warranty administration.
This list is not exhaustive. A design-build job may shift design fees into the contractor's scope, while a CM-at-risk job may leave permits with the owner. Always confirm responsibility in the contract and the Division 01 specifications.
If you want a checked list against your own plans, construction takeoff services can help you quantify the time-based items. For a full preliminary package, preliminary estimating services will build the line items and apply the right durations.
Time-based items like supervision and temporary facilities should be priced by duration, not by a percentage. A 12-month schedule needs a different number than a 6-month schedule for the same scope.
How to Estimate Preliminary Costs
Estimating preliminary costs follows the same discipline as any other part of a takeoff: define the scope, quantify it, price it, then apply adjustments. Work through these steps in order so nothing gets double-counted or missed. The preliminary costs definition is the sum of all costs incurred before physical construction begins, including mobilization, temporary facilities, supervision, permits, insurance, bonds, and closeout. These are often called general conditions or general requirements costs.
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Review the contract documents. Read the general conditions, supplementary conditions, division 01 specifications, and the schedule. These define which items the contractor must carry, who pays for permits, and how long the project runs. A 14-month schedule carries roughly twice the supervision and temporary facility cost of a 7-month schedule on the same scope.
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Identify required preliminary items. List every item the contract obligates you to provide: mobilization, temporary facilities, temporary utilities, supervision, safety, quality control, permits, insurance, bonds, and closeout. Cross-check against the specifications so an owner-furnished item does not end up in your number.
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Quantify durations. Most preliminary costs are time-based. Convert the schedule into months or weeks for each item: supervision man-months, temporary power months, crane rental months, temporary toilet service weeks. Duration is the single biggest driver of preliminary cost.
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Assign unit costs or lump sums. Price time-based items with unit rates (per month, per week, per man-hour) and fixed items as lump sums. For temporary facilities, do a specific line-item takeoff: count offices, trailers, storage, fencing linear feet, and walkway panels rather than guessing a percentage.
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Apply escalation and contingency. Escalation adjusts costs from the estimate basis date to the midpoint of construction. Contingency covers unknowns appropriate to the estimate class. An AACE estimate class sets the expected accuracy range: a Class 5 conceptual estimate might carry 30–50% contingency, while a Class 1 definitive estimate might carry 5–10%.
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Summarize and reconcile. Roll the items into a summary, then sanity-check the total against a percentage of total cost and a per-square-foot factor. If the line-item total and the percentage check disagree by a wide margin, find out why before you submit.
The preliminary cost formula pulls the pieces together:
Preliminary Costs = (Mobilization + Temporary Facilities + Supervision + Permits + Insurance + Bonds + Closeout) × (1 + Escalation) × (1 + Contingency)
Use this as a framework, not a substitute for takeoff. An order of magnitude estimate or conceptual estimate built early may rely on percentage factors, while a detailed preliminary estimate should be built from quantities and durations. If you need a second set of eyes on a preliminary estimate or a budget estimate for an owner, that review usually pays for itself before bid day.
Duration drives preliminary cost more than any other variable. Confirm the construction schedule before you price supervision or temporary facilities.
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Construction Preliminary Cost Breakdown
The table below shows a typical construction preliminary cost breakdown by category, expressed as a percentage of total preliminary cost. Use it as a cross-check after you build the line items, not as the estimate itself.
| Category | Typical % of Preliminary Cost | Basis |
|---|---|---|
| Mobilization | 5–15% | Fixed, one-time |
| Temporary facilities | 10–20% | Time-based |
| Temporary utilities | 5–10% | Time-based |
| Supervision and project management | 30–50% | Time-based |
| Safety and quality control | 5–10% | Mixed |
| Permits and fees | 5–15% | Fixed |
| Insurance and bonds | 5–10% | Fixed or value-based |
| Closeout | 2–5% | Fixed |
Supervision and project management is usually the largest single component because it scales with duration and staffing. A project with a full-time superintendent and a part-time project manager for 12 months will carry a far higher supervision percentage than a 6-month tenant fit-out.
These percentages vary by project type, size, and duration, so treat them as a range, not a rule. Some costs are fixed regardless of schedule — permits, fees, and bond premiums are set at the start. Others are time-based and grow with every month of construction: supervision, temporary facilities, temporary utilities, and equipment rentals. When you review preliminary expenses in construction, separate fixed from time-based items first, because that split tells you where schedule changes will hurt. For contractors comparing preliminary costs for contractors across multiple bids, a percentage check against a detailed takeoff catches both under- and over-pricing. If you want the line items built and priced, preliminary estimating services and construction cost estimating can produce a bid-ready breakdown.
A quick preliminary cost per square foot check works for early budgeting, but the category percentages above only reconcile after the line items are priced.
Preliminary Cost per Square Foot
Preliminary cost per square foot varies widely by project type, region, and duration, so any single number is only a starting point. For early budgeting, typical U.S. ranges for preliminary costs alone are $5–$25 per square foot for commercial buildings, $3–$15 per square foot for residential, and $2–$10 per square foot for industrial. These ranges cover preliminary costs only — mobilization, temporary facilities, supervision, permits, insurance, bonds, and closeout — not total construction cost. They vary by region, scope, and date, so confirm them against current local pricing before you rely on them.
High-rise, healthcare, and data center projects tend to sit at the higher end. Longer durations, phased occupancy, infection-control or commissioning requirements, and heavier supervision staffing all push preliminary costs up. A hospital fit-out with 18 months of supervision and continuous ICRA compliance will carry a much higher per-square-foot preliminary cost than a warehouse of the same footprint.
A preliminary cost calculator or per-square-foot factor is a fast sanity check, but it cannot replace a detailed takeoff. Factors miss project-specific items like a tower crane, a temporary pedestrian bridge, or a full-time safety officer. Build the line items first, then divide the total preliminary cost by gross floor area to get your actual per-square-foot figure. That number is defensible because you can trace it back to quantities. For commercial projects where these factors are used most often, commercial estimating services and preliminary estimating services can build the takeoff behind the factor.
Always state the basis of a per-square-foot preliminary figure — gross area, project type, and duration — or the number will be misread.
Preliminary Cost Estimate Example
This is a worked example only. Your numbers will differ by region, scope, market conditions, and project duration. Use it to see how the math flows from line items to a per-square-foot figure.
Example: 50,000 SF commercial office building, 12-month schedule
| Line item | Amount |
|---|---|
| Mobilization | $50,000 |
| Temporary facilities | $120,000 |
| Temporary utilities | $40,000 |
| Supervision | $400,000 |
| Safety | $30,000 |
| Quality control | $25,000 |
| Permits | $80,000 |
| Insurance and bonds | $60,000 |
| Closeout | $20,000 |
| Subtotal | $825,000 |
Add the line items: $50,000 + $120,000 + $40,000 + $400,000 + $30,000 + $25,000 + $80,000 + $60,000 + $20,000 = $825,000.
Apply escalation at 3% for the 12-month schedule: $825,000 × 1.03 = $849,750. Escalation accounts for labor and material price movement between the estimate date and the midpoint of construction.
Apply contingency at 10%: $849,750 × 1.10 = $934,725. Contingency covers unknowns at this stage, not scope you already know about.
Divide by gross floor area: $934,725 ÷ 50,000 SF = $18.69 per SF.
The preliminary cost formula is: (Sum of line items × escalation factor × contingency factor) ÷ gross floor area = preliminary cost per SF. If you need this run against your own plans and schedule, a preliminary estimating service can build the line items and apply duration-based escalation. For early-stage feasibility numbers before design is fixed, budget estimating services fit better.
This example assumes a 12-month schedule and a 10% contingency. A 24-month schedule changes escalation, and a design that is still at schematic level usually needs a higher contingency.
Common Mistakes in Preliminary Cost Estimating
- Underestimating supervision duration or salary burden. Supervision is usually the largest preliminary line item. If you price 12 months of superintendent time but the schedule slips to 15, the estimate is short by 25% of that line. Include payroll burden (taxes, insurance, benefits) on top of base salary, not just the hourly rate.
- Forgetting escalation on multi-year projects. A 30-month schedule means labor and material prices at month 30 differ from today. Apply escalation to the portion of work performed in later periods, or to the whole subtotal if you cannot phase it.
- Omitting permit and impact fees. Building permits are obvious; impact fees, utility connection fees, fire marshal review, and school or traffic mitigation charges are not. Call the authority having jurisdiction and confirm the fee schedule before you finalize.
- Using a percentage of total cost without adjusting for duration or complexity. A flat 5% of hard cost works for one project and fails on the next. A 6-month tenant improvement and a 36-month hospital have very different preliminary costs for contractors, even at the same hard cost.
- Missing temporary utility responsibility. Confirm whether the owner provides power and water or whether you meter and pay for them. Temporary power, lighting, water, and heating can be owner-supplied, contractor-supplied, or split by phase.
- Skipping closeout costs. As-built drawings, O&M manuals, training, spare parts, and final cleaning are real preliminary expenses in construction. They are small individually but add up, and they are easy to forget when you are focused on mobilization and supervision.
A second set of eyes catches these before bid day. An estimate review walks the line items against the schedule and scope, and a preliminary estimating service can rebuild the estimate from the plans if you want a clean baseline.
Contingency and allowance are not the same thing. An allowance covers known scope with unknown price; contingency covers unknown scope. Do not double-count them.
Preliminary Costs by Project Type
Preliminary costs in construction scale with duration, complexity, and regulatory load, not just with square footage. A 20,000 SF medical office and a 20,000 SF warehouse carry very different preliminary budgets even though the floor area matches. The preliminary costs definition remains the same across project types, but the specific line items and their magnitudes shift.
Residential projects carry the lightest preliminary load. Supervision is often the builder or a working foreman rather than a full-time superintendent. Permits are usually a single residential building permit with trade sub-permits, and the schedule runs 6 to 12 months. Temporary facilities are minimal: a storage container, a portable toilet, and a temporary power pole.
Commercial projects add supervision depth, longer schedules, and more complex temporary facilities. A 12 to 24-month schedule means a full-time superintendent plus a project manager, a site office trailer, temporary fencing, and separate metering for power and water. Permits multiply: building, electrical, plumbing, mechanical, fire, and sometimes separate right-of-way or grading permits.
Industrial projects drive heavy mobilization. Cranes, rigging, and specialized equipment move on and off site, and safety programs include lockout/tagout, confined space, and hot work permits. Testing and inspection is extensive: weld testing, concrete cylinder breaks, coating thickness, and commissioning of process systems. These items belong in the preliminary cost items list, not in the trade packages.
Infrastructure projects carry traffic control, environmental compliance, and long durations. Lane closures, flaggers, stormwater pollution prevention plans, and erosion control are ongoing costs, not one-time setup. A 36-month schedule also means escalation applies to a large share of the work.
Healthcare and data centers have their own preliminary categories. Healthcare adds infection control risk assessment (ICRA), negative air machines, and phased construction around occupied spaces. Data centers add commissioning agents, integrated systems testing, and strict temporary humidity and temperature control. Both need these in the preliminary budget from day one.
If you want the preliminary and general costs benchmarked against comparable projects in your sector, estimating by project type shows how the line items shift, and a preliminary estimating service can build the budget around your specific duration and regulatory requirements.
Duration drives preliminary cost more than floor area. Two projects at the same square footage can differ by 50% or more in preliminary cost if one runs 8 months and the other runs 24.
Preliminary Costs in Construction PDF: What to Include
A preliminary costs in construction PDF should open with a cover page showing the project name, location, estimate class, date, and preparer. Follow it with a short project description: building type, gross floor area, number of stories, structural system, and MEP scope. List your assumptions next — wage rates, productivity factors, escalation, and site conditions. Then present the detailed breakdown organized by CSI MasterFormat Division 01, covering mobilization, temporary facilities, supervision, permits, insurance, and closeout. Close with a summary page that rolls the divisions into a total and shows cost per square foot.
Include a dedicated exclusions and clarifications section. State what the estimate does not cover: hazardous material abatement, owner-furnished equipment, utility company charges, and design fees. Clarify that quantities are based on the documents listed, and that pricing reflects the stated date and location. This protects you when the owner or GC compares your number to another bid.
A sample table of contents for a construction preliminary cost breakdown looks like this:
| Section | Contents |
|---|---|
| 1 | Cover page and project data |
| 2 | Project description and scope |
| 3 | Assumptions and clarifications |
| 4 | Division 01 preliminary cost breakdown |
| 5 | Summary and cost per SF |
| 6 | Exclusions |
| 7 | Attachments and backup |
PDFs are often required for bid submissions or owner reviews because they lock the formatting and prevent edits. Some contractors use a preliminary cost calculator to generate PDFs quickly, but always review the output for missing line items. If you need a bid-ready preliminary estimate, consider preliminary estimating services or bid estimating services.
If your PDF does not state the estimate class and basis of pricing, expect the reviewer to treat it as a low-confidence number.
When to Use a Professional Preliminary Estimate
Use a professional preliminary estimate when the project exceeds $500,000, when the scope is complex (MEP-intensive, phased occupancy, or unusual structural systems), or when you are bidding competitively and need a defensible number. Below that threshold, a well-built preliminary cost calculator or in-house spreadsheet can work if you have reliable unit prices. Above it, the cost of a wrong assumption usually exceeds the fee for a professional review.
A professional estimator brings three things you may not have in-house. First, an accurate takeoff from the drawings and specifications, measured to standard methods. Second, correct unit prices for labor, material, and equipment, adjusted for your region and date. Third, local conditions: union versus open shop, permit fees, prevailing wage, and seasonal productivity. These are the variables that move a preliminary estimate by 10–20% in either direction.
For contractors who need a number fast, Scope Precision Estimate offers same-day quotes, bid-ready deliverables in 48 hours, and 20% off for new clients. Turnaround is 24–48 hours for most projects, with rush available. We provide preliminary estimating services, construction cost estimating, and budget estimating services so you can compare a conceptual number against a detailed budget at the same scope.
A professional preliminary estimate is not a substitute for a full bid estimate, but it gives you a reliable basis for go/no-go decisions, owner budgets, and early subcontractor outreach. If you are a contractor bidding multiple jobs, the time saved on takeoff alone often justifies the fee.
Ask for the estimate class and the basis of pricing in writing. A number without those two items is not a preliminary estimate; it is a guess.
Frequently asked questions
What is the difference between preliminary costs and general conditions?
In U.S. practice the two overlap heavily. General conditions (often CSI MasterFormat Division 01) are the contractual, administrative and supervisory requirements: project management, submittals, RFIs, scheduling, closeout. Preliminary costs is the broader commercial term used in many markets for everything it costs to run the job site, including general conditions plus site setup, temporary utilities, hoisting, security, cleaning and site overheads. On a bid form you may see one line called "General Conditions" or "Preliminaries" covering the same money. What matters is that your scope list is complete, not what the line is named.
How do you calculate preliminary costs in construction?
Build them in three buckets. One-time costs: mobilization, temporary fencing, site office setup, signage, initial cleaning. Time-related costs: supervision salaries and burden, temporary power and water, hoisting, toilets, security, winter protection, equipment rental, multiplied by the number of months on site. Closeout costs: demobilization, final cleaning, punch list labor, temporary facility removal. Example: a 12-month job with $18,000 per month of time-related preliminaries plus $45,000 one-time and $20,000 closeout gives $216,000 + $45,000 + $20,000 = $281,000. Divide by direct cost to get your percentage. For a structured takeoff of these items, see our preliminary estimating services.
What percentage of construction cost is preliminary?
As a working range, preliminaries typically run about 5–15% of direct construction cost, and higher on short, complex or constrained projects. A simple warehouse on a 6-month schedule may sit near the low end. A downtown high-rise, hospital fit-out or phased school renovation with a 24-month duration, crane, hoisting and tight site logistics can exceed 15%. The percentage is an output, not an input: estimate the monthly burn rate and duration first, then check the resulting percentage against your historical jobs. Regional labor rates, union agreements and site access all move the number.
What items are included in preliminary costs?
Typical items: project management and superintendent salaries with burden, project engineer and safety officer time, site office and storage, temporary fencing and gates, temporary power, water and lighting, temporary toilets and wash stations, hoisting (crane, hoist, forklift), scaffolding and access, security and cameras, dust and noise control, street and sidewalk permits, traffic control, winter protection and temporary heat, temporary roads and parking, first aid and PPE, dumpsters and progressive cleaning, surveying and layout, testing and inspections, and final cleaning and demobilization.
Are preliminary costs the same as soft costs?
No. Soft costs are owner-side costs that sit outside the construction contract: design fees, permits and impact fees, legal, financing and interest, insurance, marketing and leasing, and owner's contingency. Preliminary costs are contractor-side costs of executing the work and are normally inside the construction contract value. The two can look similar on a development pro forma, and some owners track them in one column, but they are estimated by different people and priced differently. Keep them separate so you can compare contractor bids on equal terms.
How do preliminary costs vary by project type?
Duration and site constraints drive the variation. A single-family home may carry a small monthly preliminary load for 6–9 months with no crane and minimal supervision. A mid-rise multi-family project runs 14–24 months with a full site team, hoist and phased trades. Healthcare and data center work adds commissioning, infection control or security escorts and extended supervision. Industrial and manufacturing plants add heavy rigging, temporary power distribution and permit-heavy site logistics. Renovations and occupied-space fit-outs often carry the highest percentage because protection, phasing and off-hours work multiply the monthly rate.
What is a preliminary cost estimate?
A preliminary cost estimate is an early-stage estimate prepared before full design documents exist, used to test feasibility and set a budget. In AACE terms it usually falls in Class 4 or Class 5, with expected accuracy ranges of roughly -15% to -30% on the low side and +20% to +50% on the high side, depending on the class and how much design is complete. It relies on parametric or elemental methods: cost per square foot, cost per unit, cost per bed or per key, plus a separately built preliminary package. It is not a bid.
Can I use a preliminary cost calculator for my project?
You can use one for a first sanity check, but treat the output as a placeholder. Most calculators apply a single percentage to a total cost, which ignores duration, site logistics, hoisting, phasing and local labor rates, the four things that actually move preliminaries. A better approach is to build a monthly rate for your specific project and multiply by the schedule duration. If you want the number to hold up in a budget or a lender package, have it built from your drawings and schedule by an estimator. Send us the plans and we can return a bid-ready preliminary package.